Cable support for the bucket attachment of a stick clam excavator or the like



May 5, 1970- G W.'MORK ETAL 3,510,018

CABLE SUPPORT FOR THE BUCKET ATTACHMENT OF A STICK CLAM EXCAVATOR OR THE LIKE Filed Feb. 27, 1968 INVENTOR GEORGE W-MORK CARLF.NOVOTNY ATTORNEY United States Patent 3 510,018 CABLE SUPPORT FOR THE BUCKET ATTACH- MENT OF A STICK CLAM EXCAVATOR OR THE LIKE George W. Mork, South Milwaukee, and Carl F. Novotny, Milwaukee, Wis, assiguors to Bucyrus-Erie Company, Milwaukee, Wis., a corporation of Delaware Filed Feb. 27, 1968, Ser. No. 708,619 Int. Cl. B66c 3/16 US. Cl. 214-147 5 Claims ABSTRACT OF THE DISCLOSURE A support for the bucket attachment of a stick clam excavator includes a first bracket pivotally mounted on the stick and a second bracket on the bucket attachment. The second bracket is suspended from the first by two parallel vertical cables which lie in the plane of movement of the stick. The ends of the cables are held in sleeves on the brackets, and only a short portion of each cable is exposed between the brackets. The cables provide sufficient columnar strength to allow the stick to be used to force the bucket attachment downwardly, but are flexible enough to allow for some movement in a transverse plane to compensate for ground irregularities. The brackets have facing surfaces which are engageable to limit transverse movement, side portions of one surface being angled to come flat against the other surface when they engage.

BACKGROUND OF THE INVENTION This invention relates, but is not necessarily limited to, excavators of the stick clam type in which a bucket attachment is mounted or supported on the end of a live stick in such a manner that the stick can be used to force the bucket downwardly into the material being excavated.

The support for the bucket attachment of such a machine should fulfill several important requirements. First, it should of course provide sufiicient rigidity 0r columnar strength to allow the stick to force the attachment downwardly. Second, it should allow the attachment to pivot relatively freely in the plane of the stick so that the attachment remains vertical during raising and lowering of the stick. Third, it should provide for some transverse pivotal movement of the attachment to accommodate for uneven ground conditions; but this movement should be positively limited to prevent transverse buckling when the attachment is being forced downwardly and to prevent or damp oscillations during swing movements. Fourth, the support should be strong, but should also be as simple as possible both from the standpoint of economy and to reduce the possibility of malfunction or damage during hard use.

SUMMARY OF THE INVENTION It is the general object of this invention to provide a unique type of support for the bucket attachment of a stick clam excavator or the like that fulfills all of the above requirements.

One particular feature of the invention lies in the use of a short cable supporting member which provides sufficient columnar strength for digging while still providing enough flexibility to allow for limited transverse movement, the

use of a cable for such a purpose representing a sharp departure from usual cable applications.

Another feature is the use of two cables lying in the plane of movement of the stick to provide additional strength while allowing and restricting transverse movement to the desired plane.

Still another feature is the use of brackets with facing surfaces that are engageable to limit transverse movement of the bucket attachment, preferably with angled portions on one surface so that the two come flat against one another upon a limiting engagement.

Still another feature is the use of sleeves to mount and support the cable ends. The sleeves provide firm support, yet make it relatively simple to control the exposed length of the cable and, therefore, to establish the desired degree of flexibility.

Other objects, features and advantages will appear from the description of the preferred embodiment which follows.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view in elevation, 'With parts shown broken away and in cross section, showing a bucket attachment connected to the tip of the stick of an excavator by means of a support constituting a preferred embodiment of the invention, and

FIG. 2 is an enlarged fragmentary end view of the support of FIG. 1, with parts shown broken away and in cross section and with an alternative position of the bucket attachment illustrated in broken lines.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, the reference numeral 1 designates the tip of the stick of a stick clam excavator, which is in the usual fashion movable upwardly and downwardly in the plane of the paper as seen in the drawing. The construction and operation of such machines is well known to those skilled in the art, so that the entire machine has not been shown and will not be described. A more detailed showing and description of one particular form of such a machine may be found in the copending applications: (1) of George W. Mork and Carl F. Novotny for Hydraulic Actuated Clamshell Bucket Attachment for Stick Clam Excavators or the Like, Ser. No. 702,728, filed Feb. 2, 1968; and (2) of George W. Mork for Rocker Support for Bucket Attachment, Ser. No. 702,708, filed Feb. 2, 1968, now Pat. No. 3,462,029. Further, although the support of the invention is particularly intended for use in attaching a bucket attachment to the end of a stick which is in turn mounted on a boom, it will be obvious that there might be situations in which it is desired to mount a bucket attachment in the same manner directly on the tip of a boom. The term stick as used herein is, therefore, intended to include sticks per se and other comparable boom or stick-type elements as well.

The reference numeral 2 in the drawings designates, in general, a hydraulically actuated bucket attachment of the type and construction shown and described fully in the aforementioned copending application of George W. Mork and Carl F. Novotny, Ser. No. 702,728. It includes, in general, a hydraulic cylinder 3 which has a tubular housing 4 attached to the rod end thereof. A cross head 5 extends outwardly through slots on both sides of the housing 4 and is vertically movable by means of the extensible and retractable rod (not shown) of the cylinder 3. A pair of bucket halves 6 are pivotally attached to the bottom of the housing 4 on a common pivotal axis 7, and links 8 connect the ends of the cross head 5 to respective halves 6 so that upward and downward movement of the cross head 5 opens and closes the bucket halves 6. Although this form of bucket attachment is preferred, other types of bucket attachments or equivalent load handling devices may obviously be used with the support of this invention, and the term bucket attachment is intended to include all such devices.

The support of the invention includes a first bracket designated generally by the reference numeral 9 which is pivotally attached to the tip of the stick 1 by means of a transverse pin 10 so that it and all the elements that depend from it are relatively freely pivotal in the plane of movement of the stick 1. As can be seen most clearly in FIG. 2 (wherein the tip of the stick 1 has been omitted for the sake of clarity) the bracket 9 comprises a generally U-shaped central portion 11 and opposite end plates 12, which like other connected elements to be described may be securely attached as by welding or formed integral therewith. The central portion 11 includes a horizontal base 13 which presents a downwardly facing surface and upstanding side arms 14. Aligned tubular collars 15 are provided on the arms 14 and receive the ends of the pin 10, suitable means (not shown) being provided to lock the pin 10 in place. A pair of vertical, tubular metal sleeves 16 are fixed on the base 13 and side plates 12 and are parallel and spaced from front to rear (from right to left as seen in FIG. 1) and lie in the plane of movement of the stick 1.

A second bracket designated generally by the reference numeral 17 is connected to the bucket attachment 2 and includes a central base 18, opposite and upwardly extending arms 19, and an upper support plate which extends between the arms 19 and faces the base 13 of the first bracket 9. The casing end of the cylinder 3 is attached to the bracket base 18 through a rotatable connection 21, which may be of any suitable type well known to those skilled in the art and is, therefore, shown only schematically; and a conventional hydraulic motor 22 mounted on the base 18 between the arms 19 is operated through suitable known circuitry (not shown) to cause the bucket attachment 2 to be rotated about its vertical axis as seen in the drawings to have what is known as a swivel action.

As can be seen in FIG. 2, the plate 20 has a horizontal or fiat central portion 23 parallel to, facing and spaced from the base 13, and downwardly angled side portions 24. A second pair of sleeves 25 is fixed to the plate 20 and arms 19 in alignment with respective sleeves 16.

A pair of relatively short wire cables 26 have their ends suitably tightly held, as by crimping or brazing, in the sleeves 16 and 25, and serve, alone, to support the bracket 17 and bucket attachment 2 from the bracket 9 and stick 1. The major portion of the length of each cable 26 is received in its associated sleeves 16 and 25, and there is only a relatively short portion 27 of each cable 26 that is exposed between the brackets 9 and 17. The cables 26 may be of any suitable size and type, consistent with obvious operational requirements which will appear from the discussion below.

It is of course intended that the bucket halves 6 be opened and placed on the material to be excavated, whereupon the stick 1 is used to force the bucket attachment 2 downwardly as the bucket halves 6 are being closed. During this operation, the cables 26 provide sufficient columnar strength because of the shortness of the exposed portion 27. They also, however, provide some flexibility and the bucket attachment 2 is free to pivot, for example, to the right to the position shown in broken lines in FIG. 2 or to the left to a corresponding position. This pivotal movement is in a plane transverse to the plane of movement of the stick 1, and transverse movement is essentially restricted to this plane by having the two cables 26 aligned in the plane of movement of the stick 1. Pivotal movement in either transverse direction is limited by engagement of the plate 20 and bracket base 13, and the portions 24 are angled so that they will be flat against the base 13 when the limit of desired movement is reached, as can be seen from FIG. 2.

The use of the cables 26 provides an extremely simple and obviously inexpensive construction that provides adequate support and strength while allowing a desirable limited transverse pivotal movement. It is believed that the use of cables in this sort of application wherein columnar strength is required represents a sharp departure from usual cable usage. It is not absolutely necessary, how ever, that wire cables precisely like those shown he used; and equivalent supporting members with required columnar strength and lateral flexibility might 'be substituted, the term cable being intended to cover all such equivalents.

The facing surfaces defined by the bracket base 13 and plate 20 are also important in providing for a limiting engagement that restricts pivotal movement to a desired degree, this being desirable to avoid transverse buckling during digging and excessive lateral oscillation during swinging. The inherent resilience of the cables 26 is of course also helpful in damping oscillations. Having side portions of at least one of these surfaces angled insures that the surfaces will come flat against one another to give an adequate bearing surface at the point of limiting engagement. The sleeves 16 and 25 are also important in that they provide a very convenient means of securely supporting the cables 26 over the major portion of their length; and the length of the sleeves 16 and 25 can easily be set to determine and establish the length of the exposed portions 27 and, therefore, the desired degree of flexibility.

A preferred form of the invention has been shown and described herein, but it will be obvious that previously mentioned and other modifications might be made without departure from the spirit of the invention. It is possible, for example, that a single cable might be used in certain instances. The desired angled portions for the facing bracket surfaces might be provided in the upper bracket instead of the lower bracket as shown. In view of these and other possible modifications, it is not intended that the invention be limited by the showing herein, or in any other manner, except insofar as specifically required by the following claims.

We claim:

1. In a stick clam excavator or the like having a stick that is movable in a vertical plane, a bucket attachment, and a support connecting the bucket attachment to the stick, the improvement wherein, the support comprises:

a first bracket attached to the stick; a second bracket spacer below the first bracket and connected to the bucket attachment; and a relatively short vertical cable having its end rigidly secured to and extend ing between the brackets to support the second bracket from the first bracket, said cable having a central section forming the only supporting connection between the brackets and having sufiicient columnar strength to allow the stick to be used to force the bucket attachment downwardly during an excavating operation while being flexible enough to allow transverse pivotal movement of the attachment.

2. The combination of claim 1 wherein there are two parallel cables lying in the plane of movement of the stick.

3. The combination of claim 2 wherein the first and second brackets present facing surfaces that are engageable to limit transverse movement of the bucket atachment.

4. The combination of claim 3 wherein at least a portion of at least one of the facing bracket surfaces is angled to come flat against the other during a limiting engagement.

6 5. The combination of claim 4 wherein the ends of 2,539,229 1/1951 Colburn 287-86 X the cables are secured in elongated rigid sleeves fixed 3,247,987 4/1966 Lake 214138 X on respective brackets.

G. F. ABRAHAM, Assistant Examiner References Cited 5 GERALD M. FORLENZA, Primary Examiner UNITED STATES PATENTS 544,677 8/1895 Maag 287-86 2,427,008 9/1947 Lee 287-86 X 214-656; 294 ss; 37 1s3 2 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 510, 018 Dated y 1970 Inventor(s) George W. Mork and Carl F. Novotn It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 53, "s acer" should read spaced SIGNED AND SEALED AUG4 1970 $1 .11) Meat:

mm M. m B- BuHuYnm, m. Awaiting Office lniflflicmmr of Patents 

